Brush support for mechanical road sweepers



Feb. 15, 1955 L. H. RIDDELL 2,701,389

BRUSH SUPPORT FOR MECHANICAL ROAD SWEEPERS Filed Feb. 16, 1951 FIG. 2.

United States Patent BRUSH SUPPORT FOR lVIECHANICAL ROAD SWEEPERS Leonard H. Riddell, Leeds, England Application February 16, 1951, Serial No. 211,248

Claims priority, application Great Britain February 18, 1950 3 Claims. (Cl. 15-179) This invention relates to brush supports for mechanical road sweepers. Mechanical road sweepers utilise circular revolving brooms set at an angle to sweep the road refuse to a point where it is picked up by an elevator and deposited in the vehicle body. The best form of brush is one which appears to be in a curve when looked upon in plan view, as this formation prevents trail or the leaving of litter which spills off the side of a straight set of brushes. The revolving brushes are carried on a steel shaft which is broken where the angle changes and connected by universal joints. These joints are mounted in stays which are required to lift the brushes off the ground when not required for sweeping.

To prevent trail between the respective segments of brushes where the angle changes, it is necessary to make the brush bristles interfere because when the bristles wear a gap otherwise appears. Also due to the necessity for universal joint, even on a straight brush, a gap is inevitable and bristle overlap is necessary.

This bristle overlap has been in the past a cause of considerable trouble, inasmuch as when the crossed bristles meet the stay, instead of parting and passing down each side of the stay, then tend to wrap round the shaft and shear off the bristles or lock the shafts, and the chief object of the present invention is to provide a cure for the aforesaid disadvantages.

According to the invention the brush is provided with a parting member or members at each universal joint where the angle of the brush changes, the parting member or members being formed substantially to a spiral of Archimedes. The parting member may extend from the point of crossover of the bristles and end adjacent the outside diameter of the bristles at a point where the bristles have rotated through approximately 180. Thus the parting member may be disposed in the upper half of the brush so that after leaving the parting member the bristles are free to overlap on approaching the ground and thus prevent trail.

In order that the invention may be clearly understood and readily carried into effect the same will now be more fully described with reference to the accompanying drawing, wherein:

Figure l is a plan of a brush having three sections with supports and parting members according to the invention, the brush bristles being omitted.

Figure 2 is a sectional end elevation of the support and parting member and end section of the brush shown on the right of Figure 1.

Figure 3 is a rear elevation of a portion of two adjacent brush sections with the intervening supports and parting member, the brush bristles being shown diagrammatically for clearness.

In the embodiment of the invention illustrated as applied to a brush comprising three circular brushes, a centre one 1 and two angularly disposed outer brushes 2, the brushes are mounted upon a steel shaft 3 which is broken where the angle changes and connected by universal joints mounted in stays 4 extending behind the direction of travel of the brush, the shaft and the brushes being rotated in known or suitable fashion in the direction of the arrow in Figure 2. At the points of cross-over of the bristles 5 adjacent the upper edges of the stays 4 and extending to the outside diameter of the bristles also at points adjacent the upper edges of the stays are secured parting members 6 one at each angle change of the brush. Each parting member 6 is constructed of round bar made to a spiral of Archimedes and "ice is fixed by bolts 7 to the adjacent stay 4, which has its upper edge similarly shaped to accommodate the parting member. Each of the straps 4 is shaped to conform with the curvature of the adjacent portion of the parting member 6.

The result is that the bristles are parted at the point of intersection at constant velocity and approximately in the direction of their length and consequently pass on each side of the parting member and stay when they meet it. After passing the stay, the bristles are free to overlllap on approaching the ground and thus prevent itra .9!

The example described is with reference to brush stays which push the brushes forward in the direction of the arrow A in Figure 2, but a similar construction is possible with a stay which pulls the brush forward in which case the spiral of Archimedes may extend between the two radii, i. e. the radius of the point of intersection and the radius of the diameter of the bristles, when the brush turns through instead of as described above during parting of the bristles.

The theoretical curve of the parting member can be approximated and varied at the minimum radius to prevent initial shock of the overlapped bristles engaging the parting member.

I claim:

1. In brush supports of the kind described for mechanical road sweepers, the combination with brush sections set at an angle to one another so that the end bristles of adjoining sections intersect one another and having interconnecting universal joints mounted in supporting stays, of parting members for parting the intersecting brush bristles where they pass said stays, each such parting member being formed substantially to a spiral of Archimedes with its radial dimension increasing in the direction of rotation of the brush and with at least its portion of shortest radial dimension located where it co-acts with the intersecting bristles, so as to produce a progressive separating action which commences near the base of the bristles and progresses radially outward to part the bristles without shearing the same but allowing them to intersect as they approach the ground.

2. In brush supports of the kind described for mechanical road sweepers, the combination with brush sections set at an angle to one another so that the end bristles of adjoining sections intersect one another and having interconnecting universal joints mounted in supporting stays, of parting members for parting the intersecting brush bristles where they pass said stays, each such parting member being formed substantially to a spiral of Archimedes with its radial dimension increasing in the direction of the rotation of the brush, said parting member being mounted upon its stay along the edge thereof which is approached by the bristles which edge is shaped to conform to said parting member and being arranged with at least its portion of shortest radial dimension located where it co-acts with the intersecting bristles, so as to produce a progressive separating action which commences near the base of the bristles and progresses radially outward to part the bristles without shearing the same but allowing them to intersect as they approach the ground.

3. In brush supports of the kind described for mechanical road sweepers, the combination with brush sections set at an angle to one another so that the end bristles of adjoining sections intersect one another and having interconnecting universal joints mounted in supporting stays which extend behind the brush so as to push it, of a parting member for parting the intersecting brush bristles where they pass each stay, each such parting member being formed of round rod and shaped substantially to a spiral of Archimedes with its radial dimension increasing in the direction of rotation of the brush, said parting member being detachably mounted upon its stay along the upper edge thereof which edge is shaped to conform to said parting member and being arranged with at least its portion of shortest radial dimension located where it co-acts with the intersecting bristles and being further arranged to extend angularly from approximately the point of cross-over of the bristles to a point adjacent the outside diameter of the bristles where the bristles have rotated through approximately 180", so as to produce a progressive separating action which commences near the base of the bristles and progresses radially outward to part the bristles without shearing the same but allowing them to intersect as they approach the ground.

References Cited in the file of this patent UNITED STATES PATENTS McDill May 6, 1890 FOREIGN PATENTS Great Britain of 1918 Great Britain of 1929 Great Britain of 1935 

